- The upper receiver is fully machined from an aircraft grade 6061-T6 aluminum billet in a one piece design that incorporates a full length picatinny rail (Mil-STD-1913) on the top and three additional rails on the muzzle end of the receiver, making it a full M4 style quad rail upper. The top picatinny rail is laser engraved for optic placement. There are also half-length picatinny rails available.
- 12 ½” length BAU is available in 5.56, heavy profile. 16” and 20” length BAU’s are available in both the 5.56 and 300 BLK. There are two profiles to choose from, medium and heavy. BAU’s can be interchanged in less than 3 minutes by removing the (6) captive allen screws on the bottom rail using the enclosed allen wrench.
- Long stroke variable setting gas piston system. There are three options for gas flow, and one for no gas flow. This allows for single shot operation. There is also a clean out port for the gas block between the gas cylinder, and the barrel.
Charging handle is ambidextrous, non-reciprocating, foldable, spring returned and is easily relocated from left to right side without tools by the operator.
- Model “39” Eight (8) lug bolt design with involute profile for both right and left hand versions. The extractor is positioned at 3 o’clock. This allows for a left hand version to use the same bolt by simply removing the cam pin and rotating 180 degrees and reinstalling the cam pin.
- Self-contained firing pin retention system enclosed in a rectangular bolt carrier that no longer requires a cotter pin.
- Bolted in hardened steel rail system for the bolt carrier to ride on. This allows a metal on metal wear surface for better wear characteristics and a much smoother operation.
- The ARAK-21® system allows for a folding stock to be added, as our recoil system does not extend beyond the upper receiver to fully operate. This eliminates the noise and feel of the buffer tube cycling back and forth.
ARAK-21 Upper Receiver Includes:
- ARAK-21 Upper (As Ordered)
- Shipping Box
- BAU Removal Tools
- Magazine Marker Bands
- Bolt(s) & Firing Pin(s) for Ordered Calibers
- Recoil Spring(s) for Ordered Calibers
- Uppers equipped with 12.5″ medium barrels weigh approximately 5 lbs.